JP2001329173A - Heat-conductive silicone gel composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a heat-conductive silicone gel composition having improved peelability from a releasing paper mounting and between cut faces in the case of curing a compound composition containing a silicone gel and a heat- conductive filler. SOLUTION: The objective composition contains 100 pts.wt. of a silicone gel and 50-2,500 pts.wt. of a heat-conductive filler. The heat-conductive filler is surface-treated with at least one kind of silane coupling agent selected from isobutyltrimethoxysilane, isobutyltriethoxysilane, n-butyltrimethoxysilane and n-butyltriethoxysilane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermally conductive silicone gel composition having flame retardancy and electrical insulation, and is applied as a thermally conductive component such as an electronic component, a component for electrical insulation, and the like. More particularly, the present invention relates to a thermally conductive silicone gel composition which can be easily peeled from a release liner.

[0002]

2. Description of the Related Art Conventionally, electronic components such as transistors, diodes, transformers, CPUs, and thyristors generate heat during use, and the performance of the electronic components may deteriorate due to the heat. Therefore, a heat radiator is attached to an electronic component that generates heat. Generally, a heat radiating sheet is used as an interface between the heat generating element and the heat radiating body. Recently, there is a heat conductive silicone gel as a heat dissipation sheet,
Since these are very soft, the adhesion between the heat radiator and the heat generating element is good, so that they have been widely used.

[0003]

However, recently, a heat-radiating sheet having high heat conductivity has been demanded, and it is necessary to add a large amount of heat-conductive filler to be added to the silicone gel. However, when a large amount of the thermally conductive filler is added to the silicone gel, there is a problem that the compound loses fluidity and is difficult to process, and a cured product of the compound becomes hard and brittle.

In order to solve these problems, recently, Japanese Patent Laid-Open No.
As described in JP-A-00-1616, there is an example in which a silane coupling agent having a large number of carbon atoms is used to increase the affinity with a silicone gel to thereby achieve high filling.

However, when a run coupling agent having a large number of carbon atoms is used, the surface of the cured product of the compound becomes sticky and it becomes difficult to take out the product from the release liner.
There was a problem that the cut surfaces were stuck together.

[0006] In order to solve the above-mentioned conventional problems, the present invention improves the filling property of the thermally conductive filler into the silicone gel, and furthermore, the cured product has good peeling off from the release liner, and at the same time, the cut surfaces are separated from each other. It is an object of the present invention to provide a thermally conductive silicone gel composition which has good peeling.

[0007]

In order to achieve the above object, the thermally conductive silicone gel composition of the present invention comprises a silicone gel: 100 parts by weight and a thermally conductive filler 50 per 100 parts by weight.
A composition comprising 2500 parts by weight,
The thermal conductive filler is surface-treated with at least one silane coupling agent selected from isobutyltrimethoxysilane, isobutyltriethoxysilane, n-butyltrimethoxysilane, and n-butyltriethoxysilane. And

In the above composition, the silane coupling agent is contained in an amount of 0.2 to 10% by weight based on the heat conductive filler.
Is preferably provided.

In the above composition, it is preferable that the heat conductive filler is at least one inorganic particle selected from aluminum oxide, zinc oxide, magnesium oxide and boron nitride.

[0010] In the composition, it is preferable that the average particle diameter of the thermally conductive filler is in the range of 0.010 to 10 µm.

The cured product of the compound composition of the present invention comprises
The peeling from the release liner is good, and at the same time the peeling between the cut surfaces is good.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A silane coupling agent is selected from isobutyltrimethoxysilane, isobutyltriethoxysilane, n-butyltrimethoxysilane, and n-butyltriethoxysilane, and is used for forming an alkyl group directly bonded to a silicon element. Those having 4 carbon atoms are preferred.

The method of surface treatment includes a well-known dry method, wet method, integral method and the like, and any of them may be used.

Preferably, the release liner is selected from polyester, polyimide, polyolefin, and fluorine film. These films may be coated with a fluorine compound, a silicone compound, an acrylic resin, or a melamine resin to enhance the release effect. Further, a film which has been subjected to antistatic processing and blast processing may be used.

In the present invention, a platinum compound may be added for imparting flame retardancy. Platinum compounds include chloroplatinic acid,
It is preferably at least one selected from alcohol-modified platinum chloride, a platinum olefin complex, and a methylvinylpolysiloxane platinum complex.

As the flame retardant aid, there are iron oxide, titanium oxide, aluminum hydroxide, magnesium hydroxide and the like, and one or two kinds of mixtures are suitably used.

The heat conductive silicone gel composition of the present invention is selected from isobutyltrimethoxysilane, isobutyltriethoxysilane, n-butyltrimethoxysilane, and n-butyltriethoxysilane per 100 parts by weight of the silicone gel. It is a composition compound consisting of 50 to 2500 parts by weight of a thermally conductive filler surface-treated with a silane coupling agent to be cured. The cured product has good peeling from the release liner and good peeling between cut surfaces. And a thermally conductive silicone gel composition.

[0018]

The present invention will be described more specifically with reference to the following examples.

Aluminum oxide is manufactured by Showa Denko KK AS
-30 (average particle size: 17 μm) was used. The aluminum oxide was all treated by a dry method with a silane coupling agent of 1.0% by weight of the filler. The release liner used a polypropylene film.

[0020]

Example 1 100 parts by weight of silicone gel (JCR61)
06 Toray Dow Corning Silicone Co., Ltd.) was mixed with 800 parts by weight of aluminum oxide treated with isobutyltrimethoxysilane and kneaded to obtain a liquid compound. This was press-molded to obtain a sheet.

[0021]

Example 2 100 parts by weight of silicone gel (JCR61)
06 Toray Dow Corning Silicone Co., Ltd.)
A liquid compound was obtained by adding and kneading 800 parts by weight of aluminum oxide treated with -butyltrimethoxysilane. This was press-molded to obtain a sheet.

[0022]

Comparative Example 1 100 parts by weight of silicone gel (JCR61)
06 Toray Dow Corning Silicone Co., Ltd.) was mixed with 800 parts by weight of aluminum oxide treated with methyltrimethoxysilane and kneaded to obtain a liquid compound. This was press-molded to obtain a sheet.

[0023]

Comparative Example 2 100 parts by weight of silicone gel (JCR61)
06 Toray Dow Corning Silicone Co., Ltd.)
A liquid compound was obtained by adding and mixing 800 parts by weight of aluminum oxide treated with hexyltrimethoxysilane. This was press-molded to obtain a sheet.

[0024]

Comparative Example 3 100 parts by weight of silicone gel (JCR61)
06 Toray Dow Corning Silicone Co., Ltd.)
A liquid compound was obtained by adding and kneading 800 parts by weight of aluminum oxide treated with octyltrimethoxysilane. This was press-molded to obtain a sheet.

[0025]

Comparative Example 4 100 parts by weight of silicone gel (JCR61)
06 Toray Dow Corning Silicone Co., Ltd.)
-A liquid compound was obtained by adding and mixing 800 parts by weight of aluminum oxide treated with dodecyltrimethyoxysilane. This was press-molded to obtain a sheet.

[0026]

Comparative Example 5 100 parts by weight of silicone gel (JCR61)
06 Toray Dow Corning Silicone Co., Ltd.)
-A liquid compound was obtained by adding and mixing 800 parts by weight of aluminum oxide treated with hexadecyltrimethoxysilane. This was press-molded to obtain a sheet.

The hardness, peeling strength with the film, the number of carbon atoms and the chemical formula of the alkyl group directly bonded to the silicone element,
The state results of the cut surface are shown below.

[0028]

[Table 1]

The hardness was measured with an Asker C hardness tester. The peeling force was measured with reference to JIS Z0237. (Measurement sample width: 50 mm) As for the state of the cut surface, a press-formed sheet was cut into an arbitrary size and left at room temperature for 2 weeks. After leaving the product at room temperature for 2 weeks, when removing the cut product from the release liner, it was determined whether or not the product next to the product to be removed followed or not.

As shown in Table 1 above, Comparative Example 1 is a case where the alkyl group directly bonded to the silicone element has one carbon atom, and has a low affinity with the silicone gel, so that the hardness is high and the filling property is poor. Conversely, the releasability from the film or the cut surfaces were good without sticking.

In Comparative Examples 2 to 5, the number of carbon atoms of the alkyl group directly bonded to the silicone element is 6 or more. The higher the number of carbon atoms, the higher the affinity for the silicone gel, and the lower the hardness and the better the filling property. It is. Conversely, when a silane coupling agent having a large number of carbon atoms is used, the cured product tends to be sticky, so that the releasability from the film is deteriorated. Was.

However, when the number of carbon atoms in the alkyl group directly bonded to the silicone element is four, the affinity with the silicone gel is moderate, so that the hardness, the filling property, the releasability, and the state of the cut surfaces are good. Was.

[0033]

As described above, according to the present invention, isobutyltrimethoxysilane, isobutyltriethoxysilane, n-butyltrimethoxysilane, and n-butyltriethoxysilane are selected from 100 parts by weight of the silicone gel. A composition compound consisting of 50 to 2500 parts by weight of a thermally conductive filler surface-treated with a silane coupling agent. The cured product has good peeling from the release liner and good peeling between cut surfaces. A thermally conductive silicone gel composition can be obtained.

Claims (4)

[Claims] 1. Silicone gel: a compound having a composition containing 50 to 2500 parts by weight of a thermally conductive filler with respect to 100 parts by weight, wherein the thermally conductive filler is composed of isobutyltrimethoxysilane, isobutyltriethoxysilane, n A thermally conductive silicone gel composition, which is surface-treated with at least one silane coupling agent selected from -butyltrimethoxysilane and n-butyltriethoxysilane. 2. The thermally conductive silicone gel composition according to claim 1, wherein the silane coupling agent is provided in a range of 0.2 to 10% by weight based on the thermally conductive filler. 3. The method according to claim 1, wherein the thermally conductive filler is aluminum oxide,
The thermally conductive silicone gel composition according to claim 1, wherein the composition is at least one inorganic particle selected from zinc oxide, magnesium oxide, and boron nitride. 4. The heat conductive filler has an average particle diameter of 0.01.
The thermally conductive silicone gel composition according to claim 1, which is in a range of 0 to 100 µm.